Messages in this thread | | | Date | Tue, 19 Jul 2016 10:40:16 +0100 (BST) | From | Jamie Lentin <> | Subject | Re: [PATCH v0 06/10] arm: orion5x: Add DT-based support for Netgear WNR854T |
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On Mon, 18 Jul 2016, Arnd Bergmann wrote:
> On Monday, July 18, 2016 11:44:24 AM CEST Thomas Petazzoni wrote: >> >> On Sun, 17 Jul 2016 22:41:35 +0200, Arnd Bergmann wrote: >> >>> I would assume that the PCIe port should work out of the box with the driver >> >> Unfortunately, no. The PCIe on Orion5x requires a workaround for >> reading/writing the PCI configuration space. Instead of doing MMIO >> accesses to PCIE_CONF_ADDR_OFF / PCIE_CONF_DATA_OFF, you must map a >> MBus window, which provides a memory-mapped view of the PCI >> configuration space. >> >> Definitely not impossible to implement, but the driver doesn't work >> as-is. > > Ok.
Unfortunately this isn't something I can test as the PCIe port on the SoC doesn't go anywhere in my case.
>>> We also don't seem to need any MBUS window setup for the I/O and >>> memory spaces, which greatly simplifies the driver compared to the >>> pci-mvebu one, it would be a fairly straightforward implementation >>> based on pci-host-generic.c (which unfortunately just got way >>> more complicated and might need to go on a diet). >> >> MBus windows are needed. See: >> >> mvebu_mbus_add_window_remap_by_id(ORION_MBUS_PCI_IO_TARGET, >> ORION_MBUS_PCI_IO_ATTR, >> ORION5X_PCI_IO_PHYS_BASE, >> ORION5X_PCI_IO_SIZE, >> ORION5X_PCI_IO_BUS_BASE); >> mvebu_mbus_add_window_by_id(ORION_MBUS_PCI_MEM_TARGET, >> ORION_MBUS_PCI_MEM_ATTR, >> ORION5X_PCI_MEM_PHYS_BASE, >> ORION5X_PCI_MEM_SIZE); >> >> in orion5x_setup_wins(). > > Ok, I was just looking at the wrong file, as they are set up from > common.c, not pci.c. > >> Note that we already have some Orion5x converted to DT, and that use >> PCI: board-rd88f5182.c is an example. So we could very well take Jamie >> patches as-is, and move later to a DT-representation for PCI/PCIe. > > Ah, I thought all the DT users were moved to mach-mvebu. I agree > this new patch isn't introducing anything we don't already have then, > so we can just take it, but the conversion will not be nice when > we do that.
Yes, board-wnr854t.c is a clone of the existing board-rd88f5182.c. Although I'd presume that it too would need late_initcall() or somesuch mechanism to probe PCI once the GPIO controller is available.
> I was also hoping that we could get to the point where pci_common_init() > is only used for legacy machines without DT and without multiplatform, > it seems I missed a couple of users here. > > Arnd >
-- Jamie Lentin
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